In Matthew, the Bible says, "Jesus took with him Peter and James and John, and led them up a high mountain, by themselves. And he was transfigured before them, and his face shone like the sun, and his clothes became dazzling white.” They heard the voice of God the Father: “This is my Son, the beloved; with him I am well pleased; listen to him!”

The prophet Daniel describes a similar vision. There God the Father gives his Son, “one like a human being,” dominion, glory, and kingship.

Christ’s purpose was to reassure his apostles: to strengthen their faith. In turn, St. Peter uses his experience to strengthen ours. “We had been eyewitnesses of his majesty,” he says. “We ourselves heard this voice come from Heaven, while we were with him on the holy mountain.”

“He revealed his glory in the presence of chosen witnesses and filled with the greatest splendour that bodily form which he shares with all humanity, that the scandal of the Cross might be removed from the hearts of his disciples,” the Church says in her liturgy.

“Your disciples, as much as they were capable of it, beheld your glory, O Christ our God, so that when they should see you crucified they would understand that your Passion was voluntary, and proclaim to the world that you truly are the splendour of the Father,” she says.

In addition, she says, the Transfiguration of Christ, who is head of the Church, shows what will happen to “the whole Church,” which is his body, at the end of time.

In his apostolic letter On the Rosary of the Virgin Mary, St. John Paul II proposed five new mysteries for meditation in order “to bring out fully the Christological depth of the rosary.”

In order to make it a fuller “compendium of the Gospel,” he said, we should add “a meditation on certain particularly significant moments in Christ’s public ministry.” He called them the Luminous Mysteries, or the Mysteries of Light, to be inserted after “reflection on the Incarnation and the hidden life of Christ (the Joyful Mysteries) and before focussing on the sufferings of his Passion (the Sorrowful Mysteries) and the triumph of his Resurrection (the Glorious Mysteries).”

The Pope chose “(1) Christ’s baptism in the Jordan, (2) his self-manifestation at the wedding of Cana, (3) his proclamation of the kingdom of God, with his call to conversion, (4) his Transfiguration, and finally, (5) his institution of the Eucharist, as the sacramental expression of the Paschal Mystery.”

“Each of these mysteries,” he said, “is a revelation of the kingdom now present in the very person of Jesus.”

However, he said, “the mystery of light par excellence is the Transfiguration, traditionally believed to have taken place on Mount Tabor. The glory of the godhead shines forth from the face of Christ as the Father commands the astonished apostles to listen to him and to prepare to experience with him the agony of the Passion, so as to come with him to the joy of the Resurrection and a life transfigured by the Holy Spirit.”

“The Transfiguration gives us a foretaste of Christ’s glorious coming, when he will change our lowly body to be like his glorious body,” says the Catechism of the Catholic Church. “But it also recalls that it is through many persecutions that we must enter the kingdom of God.”

“Peter did not yet understand this when he wanted to remain with Christ on the mountain,” St. Augustine said. “For now, Jesus says, 'Go down to toil on earth, to serve on earth, to be scorned and crucified on earth.'"

“The Church, and through her the world, will not be perfected in glory without great trials,” the Catechism explains. She will “receive her perfection only in the glory of heaven, at the time of Christ’s glorious return. Until that day, the Church progresses on her pilgrimage amidst this world’s persecutions and God’s consolations.”